The capsular polysaccharide (CPS) is a major virulence factor in many encapsulated pathogens, as it is the case for Streptococcus suis, an important swine pathogen and emerging zoonotic agent. Moreover, the CPS is the antigen at the origin of S. suis classification into serotypes. Hence, analyses of the CPS structure are an essential step to dissect its role in virulence and the serological relations between important serotypes. Here, the CPSs of serotypes 1 and 1/2 were purified and characterized for the first time. Chemical and spectroscopic data gave the following repeating unit sequences: [6)[Neu5Ac(α2-6)GalNAc(β1-4)GlcNAc(β1-3)]Gal(β1-3)Gal(β1-4)Glc(β1-]n (serotype 1) and [4)[Neu5Ac(α2-6)GalNAc(β1-4)GlcNAc(β1-3)]Gal(β1-4)[Gal(α1-3)]Rha(β1-4)Glc(β1-]n (serotype 1/2). The Sambucus nigra lectin, which recognizes the Neu5Ac(α2-6)Gal/GalNAc sequence, showed binding to both CPSs. Compared with previously characterized serotype 14 and 2 CPSs, N-acetylgalactosamine replaces galactose as the sugar bearing the sialic acid residue in the side chain. Serological analyses of the cross-reaction of serotype 1/2 with serotypes 1 and 2 and that between serotypes 1 and 14 suggested that the side chain, and more particularly the terminal sialic acid, constitutes one important epitope for serotypes 1/2 and 2. The side chain is also an important serological determinant for serotype 1, yet sialic acid seems to play a limited role. In contrast, the side chain does not seem to be part of a major epitope for serotype 14. These results contribute to the understanding of the relationship between S. suis serotypes and provide the basis for improving diagnostic tools.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4861414 | PMC |
http://dx.doi.org/10.1074/jbc.M115.700716 | DOI Listing |
Biotechnol Adv
January 2025
TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin, PR China; Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, PR China; Nankai International Advanced Research Institute, Nankai University, Shenzhen, China. Electronic address:
Protein glycosylation, which involves the addition of carbohydrate chains to amino acid side chains, imparts essential properties to proteins, offering immense potential in synthetic biology applications. Despite its importance, natural glycosylation pathways present several limitations, highlighting the need for new tools to better understand glycan structures, recognition, metabolism, and biosynthesis, and to facilitate the production of biologically relevant glycoproteins. The field of bacterial glycoengineering has gained significant attention due to the ongoing discovery and study of bacterial glycosylation systems.
View Article and Find Full Text PDFCurr Cancer Drug Targets
January 2025
Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, Nilgiris, Tamil Nadu, India.
Cancer manifests as uncontrolled cell proliferation. Tankyrase, a poly(ADP-ribose) polymerase member, is vital in Wnt signal transmission, making it a promising cancer therapy target. The Wnt/β-catenin pathway regulates critical biological processes like genomic stability, gene expression, energy utilization, and apoptosis.
View Article and Find Full Text PDFJ Org Chem
January 2025
Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstrasse 11, 48149 Münster, Germany.
Xanthine nucleosides play a significant role in the expansion of the four-letter genetic code. Herein, 7-functionalized 8-aza-7-deazaxanthine ribo- and 2'-deoxyribonucleosides are described. 2-Amino-6-alkoxy nucleosides were converted to halogenated 8-aza-7-deazaxanthine nucleosides by deamination followed by hydroxy/alkoxy substitution.
View Article and Find Full Text PDFJ Med Chem
January 2025
Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong SAR 999077, China.
CDK4/6 inhibitors are effective in treating HR/HER2 breast cancer but face limitations due to therapeutic resistance and hematological toxicity, particularly from strong CDK6 inhibition. To address these challenges, designing selective inhibitors targeting specific cyclin-dependent kinases (CDK) members could offer clinical advantages and broaden CDK inhibitor indications. However, the highly conserved binding pockets of CDKs complicate selective targeting.
View Article and Find Full Text PDFProteins
January 2025
Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India.
Short-length peptides are used as therapeutics due to their high target specificity and low toxicity; for example, peptides are designed for targeting the interaction between oncogenic protein p53 and E3 ubiquitin ligase MDM2. These peptide therapeutics form a class of successful inhibitors. To design such peptide-based inhibitors, stapling is one of the methods in which amino acid side chains are stitched together to get conformationally rigid peptides, ensuring effective binding to their partners.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!